The International Union of Soil Sciences (IUSS) is the global union of soil scientists. The objectives of the IUSS are to promote all branches of soil science, and to support all soil scientists across the world in the pursuit of their activities. This website provides information for IUSS members and those interested in soil science.

World of Soils

The diversity of soils all over the world is amazing!
Imagine all the different soil types in different countries and landscapes showing their particular functions and forms of appearance.

All the soil experts cooperating within the world wide framework of the IUSS have collected a huge number of great pictures of soils all over the world.

This site will give insight into the diversity and beauty of the world of soils on our planet.

As part of the celebration of the International Year of Soils IUSS is initiating to collect a set of beautiful soil pictures of different soil types from all over the world.

Commissions are asked to contribute but individuals who may wish to share profile pictures and related landscapes are welcome!

The width of the pictures should be at least 1000px (landscape) and the lengths of text should be about 250 characters, and include the location, the soil type, given in the World reference base or Soil Taxonomy, the major properties and functions of the soil.

If you wish to donate to the collection, please send it to the IUSS Secretariat with subject “World of Soils”

Palaeosol from Italy

Palaeosols and relic features in polygenetic soils: Records of past environmental conditions and their duration

Two dark palaeosols embedded in an alluvial fan in Calabria, Italy

A paleosol indicates a period of geomorphological stability, whereas a sediment layer between two paleosols indicates a dynamic phase in the landscape history. Additional information can be obtained from the morphological, chemical and mineralogical properties of a palaeosol, and various biological objects contained therein (phytoliths, molluscs, charcoal, stable chemical vegetation remains etc.).

All these may be used as indicators of the environmental conditions that prevailed during the period in which the palaeosol developed.

Thus, the main questions to be answered in palaeopedological studies are: 1. How much time is required to produce the stage of soil development that we see in this palaeosol? 2. Which environmental conditions may produce the morphological features and chemical, mineralogical, biological and other characteristics that we observe in this palaeosol?
In addition, also many surface soils that seem to be contemporary soils contain features that formed under past environmental conditions and may thus serve as palaeo-environmental indicators. In this case, the concept of soil features adjusting to new environmental conditions at different rates is very useful (Yaalon, 1971: 29-39, available at https://sites.google.com/site/palaeopedology/electronic-resouces/paleopedology-origin-nature-and-dating-of-paleosols ).

Yaalon (1971) distinguished (i) rapidly adjusting features (adjusting within some hundreds of years), (ii) slowly adjusting features (adjusting within some thousands of years), and (iii) persistent features (showing no changes over ten thousands to millions of years).
The lower the rate at which a certain soil property in a polygenetic surface soil adjusts to new environmental conditions, the larger is the extent to which this property is still determined by the former environment in which it formed. Thus, knowledge on the rates at which soil properties adjust may be used to estimate the time at which a significant environmental change took place, based on the degree of overprinting of the different kinds of soil features adjusting at different rates in a polygenetic soil. Secondly, it can be concluded that the present functioning of polygenetic surface soils is also influenced by soil properties that developed under former environmental conditions.

Chernozem from Hungary

Chernozems are representing one of the most fertile soil types of the Earth. The deep, dark, organic matter rich topsoil has a high capacity to store nutrients and water.

Chernozems provide favorable medium for natural and agricultural plants and other living organisms.

They correlate with the deep Mollisols of Soil Taxonomy.

To mark the celebration of the International Year of Soils, 2015 Hungary donated a soil mononlith to FAO. The monolith is from the same Chernozem that starts the “World of Soils” picture collection of IUSS. This Chernozem has been nominated also as the national soil of Hungary, when the country performed the presidency semester of the EU. All countries and or states are encouraged to send their national or state soil pictures with short description to the World of Soils collection.